Deep excavations often require a support of excavation system (SOE) which acts as a retaining wall or similar structure against adjacent earth. The SOE may be a temporary or permanent installation.
Tieback assemblies are commonly used to retain the SOE in resisting lateral loads resulting from adjacent earth pressure. Tieback assemblies are introduced through the SOE into the adjacent earth with an anchor at the leading end and a tendon extending therefrom. The tendon extends externally of the SOE to be fixed thereagainst, either directly or through a secondary structure, such as a wale. The anchor is formed to engage surrounding earth or a cementitious grout which is deposited about the anchor. In any case, the anchor, interacting with surrounding earth directly or through deposited grout, provides a resistive force against removal of the tieback assembly through the SOE. With the fixation of the tendon against the SOE, force is transmitted between the SOE and the anchor counteracting the earth-generated lateral forces.
In typical installations, tieback assemblies extend into adjacent tracts of land having different ownership from the related excavation or work site. In addition, tieback assemblies are typically left in the ground after the completion of work. Because of the encroachment onto neighboring properties, an increasing number of government regulations and private landowners are requiring at least partial removal of tieback assemblies. As a result, easement fees, contractual penalties, and the like, are being assessed on tieback assemblies which remain fully intact in the ground after completion of the related job.